[fine] Error on generic parameters

fine/src/semantics.rs

@@ -607,12 +607,7 @@ impl<'a> Semantics<'a> {
                 continue;
             };
 
-            let declaration_type = if let Some(type_expression) = param.nth_tree(2) {
+            let declaration_type = self.type_of(*ct);
-                self.type_of(type_expression)
-            } else {
-                Type::Error
-            };
-
             environment.insert(param_name, declaration_type);
         }
 
@@ -658,6 +653,7 @@ impl<'a> Semantics<'a> {
 
             TreeKind::FunctionDecl => self.type_of_function_decl(tree),
             TreeKind::ReturnType => self.type_of_return_type(tree),
+            TreeKind::Parameter => self.type_of_parameter(tree),
 
             _ => self.internal_compiler_error(Some(t), "asking for a nonsense type"),
         };
@@ -1007,12 +1003,7 @@ impl<'a> Semantics<'a> {
         let param_list = tree.child_tree_of_kind(self.syntax_tree, TreeKind::ParamList)?;
         let mut parameter_types = Vec::new();
         for p in param_list.child_trees() {
-            let param = &self.syntax_tree[p];
+            parameter_types.push(Box::new(self.type_of(p)));
-
-            // TODO: Shouldn't this just be type_of(param)?
-            // TODO: Missing type expression means it's a generic function.
-            let parameter_type = param.child_of_kind(self.syntax_tree, TreeKind::TypeExpression)?;
-            parameter_types.push(Box::new(self.type_of(parameter_type)));
         }
 
         let return_type = match tree.child_of_kind(self.syntax_tree, TreeKind::ReturnType) {
@@ -1023,6 +1014,17 @@ impl<'a> Semantics<'a> {
         Some(Type::Function(parameter_types, return_type))
     }
 
+    fn type_of_parameter(&self, tree: &Tree) -> Option<Type> {
+        assert_eq!(tree.kind, TreeKind::Parameter);
+        match tree.child_of_kind(self.syntax_tree, TreeKind::TypeExpression) {
+            Some(t) => Some(self.type_of(t)),
+            None => {
+                self.report_error_tree(tree, "generic parameters not yet supported");
+                Some(Type::Error)
+            }
+        }
+    }
+
     fn type_of_return_type(&self, tree: &Tree) -> Option<Type> {
         assert_eq!(tree.kind, TreeKind::ReturnType);
         Some(self.type_of(tree.nth_tree(1)?)) // type expression

fine/tests/expression/generic_function.fine

@@ -0,0 +1,11 @@
+fun generic_add(x, y) {
+  x + y
+}
+
+fun test() {
+  generic_add(10, 10)
+}
+
+// @ignore
+// @no-errors
+// @eval: 20